Micrometer-gage.



SAW

A. C. MAY. 1'11ICECHETEB. GAGE. APPLICATION FILED umn, 1914.

191335652. l v `Patented Mar. 30, 1915.

UNITED STATES PATENT. oEEicE.

ALBERT-ennemis may, or'LoNnoN, ENGLAND.

MICBOMETER-GAGE.

Specification of Letters Patent.

.Application led 'April 11, 1914. Serial No. 831,181.

To all 'whom it may concer/t:

Be it known that I, ALBERT ClrAnpEs Mar, a subject of the King of Great Britain, residing at London, England, engineer, have 1nvented new and useful Improvements in Micrometer-Gages, of which the following is a specification.

This invention relates to new or improved adjusting mechanism for establishing readings or measurements on instruments such as micrometer gages, for example, but my improvements are equally applicable to other measuring instruments and apparatus where a varying speed of movement of the ram, measuring element, or its equivalent, is desired. I will therefore content myself in f describing my improvements as applied to a micrometer gage, for example, and bymeans of clutches and retarding mechamsm I am enabled to make micrometric measurements of a varying nature according to circumstances in a quicker and more accurate manner than heretofore by the operation of the one graduated barrel as commonly employed in this class of instrument.

Compound micrometer calipers have already been devised whereby by means of one set of screw gear a coarse adjustment has been obtained or registered, and by another set of screw gear mounted practically in parallel with the first named screw gear, and

y, independently operated, a finer adjustment has been obtained or registered.

By my improved mechanism I am enabled to obtain similar variable adjustment or measurement by the manipulation of the one raduated barrel acting directly on the orary micrometer screw gear, and the interposition of a clutch device whereby the second or retarding screw gear is put into operation and a finer adjustment obtained `according to the difference in the pitch of the threads employed by the manipulation of the same barrel. The arrangement of mechanism simplifies the construction of micrometer gages and extends the scope of utility; affording in the one intrument a simple and convenient means of more minute adjusti ment than has been obtainable heretofore, and

Vmicrometric measurements desired, the maalways carried out by the Y nipulation being rotation of the one graduated barrel. c

In order that m invention may be clearly understood, I w' now describe the same with the aid of the 'accompanying sheet of drawings in whichf Eigur'e 1 is a longitudinal sectional elevatlon of a micrometer gage constructed in accordance with my invention; Fig. 2 a similar view of apart of the same instrument showing parts in different positions; Figs. 3, 4 and 5 are cross sections on line :S0-3, 4-4 and 5,-5 respectively of Fig. 1 viewed as indicated by the plain arrows in that figure.

Similar letters of reference relate to like parts in all-the figures of the drawings.

Referring to the drawings, a represents the yoke carrying the ordinary anvil o between whichv point and the end of the ram c the measurements are taken.

0n the outside of the extension b1 of the yoke 11, is provided a scale as may be decided, which of course read with the scale marked g on the conical end r of the barrel a.

In the example given each unit p1 of the scale p is presumed to represent 416th of an Patented Mar. 30, 19M.

inch, and each unit g1 of the scale g Tfmth of an inch, that is to say, the conical end i' is divided into 25 equal parts. Within the yoke 'n 1s provided one or more keys c1 which fit into grooves s in the ram c to prevent the rotary movement thereof. The extension b1 is provided with an internal thread t which engages with an external thread u provided on the hollow elongated boss b. forming part of the barrel a, and freeto' rotate on the ram' or central spindle c.

a1 and in the interior of the barrel a is provided' the one half of the clutch (female end) which is used for the coarse adjustment or measurement to be registered as hereinafter more fully described. This portion of the clutch surroundsthe ram or central spindle extension d, and 'is to the intermediate Wall in the barrel a by means of' screws w, as shown clearly in Fig.` 4, and the whole may' be kept central by means of the little boss y which snugly iits the interior of the lock-nuts w and t 'e'bore e* provides a bear', fcr 1g* thereby mauitaining the concentri ity vo 'the parts.

The extension or back end of the .barrel a is provided with an internal screw-thread 2 which is of a different pitch to thatv refer t to at, t. Within this screw-threadfis pipvded the operating nut k which is put in ear'for the purpose of eectmg la fine adustment of the ram orcentral spindle e, d by means of clutch gear g, gli, as shown 1n engagement in Fig. 1. f

hrough suitab e holes or slots 8, Eig. 5, provided in, the-nut It pass the longitudinal arms i which carry the male portions and be screw-threaded as at Gand operation.

4 clutches f, f1 and g,

- lIlOVe Ain the g of' the two clutches. These arms v are connected. together by means of the bridlepiece 4, and are inclosed within the barrel by means of the cap or cover 5 which ma provided wit a central bearing or boss 7 t rough which the spindle 8 passes and may be operated by the milled head 9 for the urpose of put-l ting one orother of the c utch gear into A small key or projection 1,1 is provided on the spindle 8 whichl engages wlth a corresponding notch 12, or is in hne therewith, to insure the engagement of the respective g1' when the scale q is atzero.

To the back end of the ram or central s indle extension d is secured a ferrule or sleeve j by means of the keys c, and the beforementioned nut h is free to rotate thereon, the female portion g1 of the clutchvbeing provided at the left hand end, and the whole being retained in position by means o f lock-nuts 10. 1

If now onlya coarse adjustment or measurement is required, and presuming 1n this case that 40 threads to the inch areemployed at t, the clutch f, f1 is in the position shown in Fi 2 the milled head'9 having been to the left for the purpose of disenaging the clutch g, g1 andengagmg, as beore stated, clutch f, f1, the barrel a will now work precisely as an ordinary micrometer gage, the retardingmechanism being locked of the engagement of theclutch f, f1 and the arms e'. extending through the nut h. The whole will rotate about the ram c and extensiond,and as the clutch g, g1 is out of igear the nut h is free to rotate about and hollow end of the barrel a by means slide on the sleeve or ferrule y', this latter being secured against relative rotary movement upon the spindle d. The clutch f, f1 is now m gear and rotates with the barrel a, and no movement of arms i with res ect to the barrel a due to the screw-threa 2 can take place, and longitudinal movement is prevented by the flange formed by the part g? of the clutch and the lock-nuts 10. The said ram isv moved simply by the engagement of the thread u working in the hollow extension b* of the yoke n, registering the measurement as in the ordinary micrometer gage according to the pitch of the thread employed at t. If more accurate or fine ad]ustment or measurement is required, the micrometer is used as above described setting the same to the nearest 316th of an inch, the scale q being at zero, and after taking note of the reading on the scale p the clutch g, g* is put-into ear as shown in Fig. 1, whereby the nut It 1s locked to the ferrule or attached to the ram c or central spindle extension d.

It will be observed that the ram c is revented from rotating by means of the eys t, therefore the barrel a will rotate on the nut move the ram c in a contrary direction to that produced by the thread t connecting the parts b and b1. The combined movements produced by the engagement of the parts b1 and b and the thread 2 of the barrel a with the nut k has a retarding effect on the rain4 c, and according to the differences adopted in the pitch of the threads employed, so may this retarding effect lbe increased or decreased as desired. The effect therefore of turning the barrel a in one direction is to project the ram c forward in the direction of the feathered arrow D, while at the Asame time the effect of the direct englgement of the screw-thread 2 with the ed nut h is to project the ram in the opposite direction as indicated by the feathered arrow E, thus producing a retarding influence on the ram. It follows too that when .the clutches g, g1 are in gear for effecting space 1s formed between the end 'of the ferrule or sleeve a1 and the spindle or ram c at the shoulder v. The ferrule or sleeve a,1 acts as a sto for the ram c on the return of the fine adJusting mechanism back to the original reading. That is to say the ram c is brought back to contact with the ferrule or sleeve a1 before disengagement or engagement of the clutchesv g, g1 or f, f1. It may be observed that in the example it is presumed that the thread on the forward part of the barrel a is an external right-handed thread (as shown) with a pitch of 40 to the inch, and that on the rear part of the said h as a fixed nut and at the same time will these finer measurements in use a barrel a an internal right-'handed thread as shown) 44; to the inch. The obvious eduction therefore is that with 40 threads the ram will be moved th of an inch per revolution of the barre and with 44% threads the ram will be moved T81- of anv inch p er revolution of the barrel a in the opposite direction, the difference is therefore which may be recorded or registered by any convenient systems of scales as at p, g for example. It will be understood that any fractional part of the T51; of an inch thus measured may be readily registered, vfor example 215 part thereof would mean an adustment or measurement equal to W10-w o an inch scale p; if, however, a finer measurement desired, say to separate the'ram c from the Y anvil o by T31; of an inch this is eiected fol every revolution of the barrel a with conditions prevailing as illustrated in Fig. 1,

that is to say the ratio of movement dueto the diii'erent conditions illustrated in Figs. 1 and 2 is 10 to 1.

In the drawing and arrangement above described of a micrometer gage it will be observed that an external thread isemployed for thecoarse adjustment or measurement, and an internal thread for the fine adjustment or measurement, and that both threads are right-handed. It will, however, be obvious that internal or external threads may be empolyed for both coarse and hne measurements, and that the same effect ma be obtained by right or left-handed threa s as may be desired in cooperation with sultable clutch gear. Also that a second set of scales may be employed to register measurements of a fine character and that a Vernier scale may be added to the instrument, these being mechanical expedients which donot depart rom the scope of the appended claims, are so obvious that they do not require illustration. Y

Claims:

1. A micrometer gage compnsmg a yoke member,aram slidably engaged w1thin thc yokemember, a graduated operating barrel rotatably mounted upon the yoke and having threaded connection therewith, means permitting free rotation of the said bar rel upon the ram adapted to prevent relatlve longitudinal movement of the same, a nutmounted upon the ram and having threaded connection with the barrel, the pitch of the threads of this latter connection being different from the pitch of the threads 'of the connection between the barrel and the yoke member, yand means by which the said nut may be secured to the ram for movement therewith or may be released from the ram and secured -to the barrel for rotation therewith. Y

2. A micrometer gage comprising a yoke member, a ram slidably engaged within the yoke member, a graduated operating barrel rotatably mounted upon the yoke and having threaded connection therewith, means permittmg free rotation of the said barrel upon the ram adapted to prevent relative longitudinal movement of the same, a nut mounted upon the ram and havin threaded connection with the barrel, the pitch of the I threads of this latter connection being different from the pitch of the threads of the connection between the barrel and the yoke member, clutch mechanism provided within the said barrel and being adapted to connect the said nut with the ram for rotation therewith or with the barrel for rotation with the same to be free with respectto the ram during this movement, and means b which the clutch mechanism may be shifts 3. A micrometer gage comprisin a yoke member, alam slidably engaged within the yoke member, a graduated operating barrel rotatably mounted upon the yoke and having threaded connection therewith, means permitting free rotation of the said barrel upon the ram adapted to prevent relative longitudinal movement of the same, a, nut mounted upon the ram andhavin threaded connection with the barrel, the pitch of the threads of this latter connection being difconnection between the barrel and the yoke member, fixed clutch members provided upon the said barrel and upon the ram, a movable clutch member mounted for axial sliding movement alone with respect to the said nut and being ada ted for engagement with either of the said ed clutch members, and an operating stem connected with the said movable clutch member and projecting exteriorly from the barrel.

f4. A Amicrometer gage comprising a yoke member, a ram slidably engaged within the yoke member, a graduated operating barrel rotatably mounted upon the yoke and having threaded connection therewith, means permitting free rotation of the said barrel upon the ram adapted to prevent relative longitudinal movement of the same, a nut mounted upon the ram and having threaded connection with the barrel, the pitch of the threads of this latter connection being different from the pitch of the threads of the i connection between the barrel and the yoke In testimony whereof I have signed my member, and means by which the said-nut nume to this specication in the presence of 10 may be secured to the ram for movement two subscribing witnesses.

. abut each other.

therewith or may be released from the ram A. l and secured to the barrel for rotation there- ALBERT CHARLES MAY with, the said barrel and ram being pro- Witnesses: vided with limiting shoulders adapted to STEPHEN EDWARD GUNYoN,

ALEXANDER EDWARD BECK. 

